[1][2][3][4] PSTVd is a small, single stranded circular RNA molecule[5] closely related to the chrysanthemum stunt viroid.

Present within the viroidal RNA is the Pospiviroid RY motif stem loop common to its genus.

Common symptoms of severe infections include color changes in the foliage, smaller leaves and spindle-like elongation.

[10] Infected tomatoes are slower to show symptoms which include stunted growth with a ‘bunchy top’ caused by shortened inter-nodes.

Fruit ripening is also affected leading to hard, small, dark green tomatoes.